Compression resistance testing machine for pelletized material

ABSTRACT

AN APPARATUS WHICH GAUGES THE COMPRESSION RESISTANCE OF A PELLET SUPPORTED BETWEEN A PAIR OF PRESSURE PLATES MOVABLY DISPOSED SO THAT ONE OF THE PRESSURE PLATES IS URGED TOWARD THE SECOND PRESSURE PLATE WHICH IS AFFIXED TO A CANTILEVERED SENSING BEAM WHICH FLEXES FROM THE COMPRESSIVE FORCE AND THE AMOUNT OF FLEXURE CAUSED THEREBY IS MEASURED AND CORRELATED AS A MEANS OF MEASURING COMPRESSIVE FORCE.

Oct. 5, 1971 GUNN EI'AL 3,610,084

COMPRESSION RESISTANCE TESTING MACHINE FOR PELLETIZED MATERIAL Filed D80. 24, 1969 3 Sheets-Sheet l Oct. 5, 1971 GUNN EI'AL 3,610,034

COMPRESSION RESISTANCE TESTING MACHINE FOR PELLETIZED MATERIAL Filed Dec. 24, 1969 3 Sheets-Sheet 2 Ila Oct. 5, 1971 Fildd Dec. 24,

UNN ETA!- COMPRESSION RESISTANCE TESTING MACHINE FOR PELLETIZED MATERIAL 3 Sheets-Sheet 5 United States Patent 3,610,034 COMPRESSION RESISTANCE TESTING MACHINE FOR PELLETIZEI MATERIAL Kenneth M. Gunn and Matthew H. Fuller, Richmond, Va., assignors to Texaco Inc., New York, N.Y. Filed Dec. 24, 1969, Ser. No. 887,854 Int. Cl. G01n 3/08 U.S. Cl. 73-94 7 Claims ABSTRACT OF THE DISCLOSURE An apparatus which gauges the compression resistance of a pellet supported between a pair of pressure plates movably disposed so that one of the pressure plates is urged toward the second pressure plate which is afiixed to a cantilevered sensing beam which flexes from the compressive force and the amount of flexure caused thereby is measured and correlated as a means of measuring compressive force.

BACKGROUND OF THE INVENTION Pelletized material such as catalyst pellets used in catalytic reforming, are manufactured, for example, by coating a metallic salt onto a support structure such as alumina. The catalyst pellet is heated over a period of time to increase its ability to resist fragmentation. Prolonged heating, however, continually lessens catalyst activity.

The manufacturers and users of the catalyst pellets must, therefore, through testing, determine an acceptable minimum strength with sufficient activity of catalyst pellets. These tests are correlated with the length of time the catalyst pellets have been heated to determine an acceptable heating period. Too short a heating period makes the catalyst pellets unable to resist fragmentation under pressure and causes the catalyst pellets to suffer from attrition in use. Attrition of a catalyst pellet is the fragmentation thereof into particles which fall into the reactor and cause channelling, i.e., rerouting of the gases to the spaces not blocked by catalyst. This causes an irregular flow pattern since the spaces filled by the fragments of catalyst are sealed off as gas passages.

Compression resistance testing machines have been developed to measure the ability of catalyst pellets to resist compression. Some of the more popular testing machines include a universal test machine, a shot catalyst crusher and a hydraulic press.

The universal test machine has about the same accuracy as the apparatus of the present invention but is slower, requiring twice the time to perform a similar test, and requires a larger initial capital outlay.

The shot catalyst crusher testing procedure is extremely slow (requiring about times the performance time associated with the present invention) and requires the placing of a catalyst pellet between a pair of flat plates. An empty funnel is balanced upon the top plate and shot is poured slowly into the funnel until the catalyst pellet fragmentates or is crushed. The amount of shot in the funnel is then weighed to determine the compressive force exerted.

The hydraulic press is hand-pumped by an operator until the pellet is either crushed or fragmentated. The load exerted by the hydraulic press is read on a maximum reading hydraulic gauge. The hydraulic press produces inaccurate results because of the sporadic, non-linear rate of load application. It is also somewhat slower to use than the apparatus of the present invention.

Patented Oct. 5, 1971 In accordance with the present invention there is de scribed a compression resistance testing machine for pelletized material in which the pelletized material is crushed between an ever-increasing force exerted by the testing machine, including an enclosure forming a platform on top with an orifice therein; a retaining strap secured to the platform on one end and having an aperture therein with at least one flat side, the aperture being disposed in axial alignment with the orifice; a screwjack, the sleeve of which is non-rotatably secured to the retaining strap in axial alignment with the aperture for reciprocal axial movement through the orifice; motor means fixedly mounted within the enclosure and non-rotatably linked to the screw of the screwjack for turning the screw in either direction; a first pressure plate mounted on the sleeve in axial alignment therewith and having a bottom rod portion with at least one flat side conforming in cross section, at least in part, to the shape of the aperture and, fitting non-rotatably through the aperture and through the orifice; a cantilevered sensing beam, the free end thereof extending above the first pressure plate and the fixed end extending over the platform; a second pressure plate in axial alignment with and spaced away from the first pressure plate, the reverse face of the second pressure plate being non-rotatably afiixed to the underside of the free end of the cantilevered sensing beam; beam restraining means for restraining the fixed end of the cantilevered sensing beam, the beam restraining means being rigidly affixed to the platform so that the fixed end of the cantilevered sensing beam thereby restricts the free end of the cantilevered sensing beam from rotating away from the first pressure plate as the first pressure plate is forced against the pelletized material between the first and second pressure plates; and gauge means in communication with the cantilevered sensing beam for measuring and indicating the movement of the cantilevered sensing beam, the gauge means being calibrated to record load exerted against the cantilevered sensing beam by the movement of the first pressure plate toward the cantilevered sensing beam, whereby a pelletized material placed between the first and second pressure plates on the obverse face of the first pressure plate is compressed by the axial advance of the sleeve as the screw is rotated by the motor means, the cantilevered sensing beam being flexed while the pelletized material resists compression, the flexure of the cantilevered sensing beam ending abruptly as the pelletized material fragmentates upon the maximum compression resistance of the pellet being exceeded, and the gauge means indicating the maximum compression resistance of the pelletized material at fragmentation.

It is an object of the present invention to provide a compression resistance testing machine which is quick and accurate in use.

It is another object of the present invention to provide a compression resistance testing machine which is capable of continuous automatic operation.

These and other objects of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing, wherein the invention will be further understood by reference thereto.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing represents preferred forms of the invention, wherein:

FIG. 1 is a perspective view of an embodiment of this invention with portions broken away to show greater detail;

FIG. 1a is a perspective view of the feed portion of an alternate embodiment of this invention;

FIG. 2 is an elevation in partial section looking along the lines 2--2 in the perspective view of FIG. 1;

FIG. 3 is a section of an alternate embodiment of the pressure plates looking along the lines 3-3 in FIG. 2 with the pelletized material in place for compression;

FIG. 4 is a section looking along the lines 4-4 in FIG. 2;

FIG. 5 is a schematic diagram of an alternate embodiment of an airline shown partially in FIG. 1;

FIG. 6 is a schematic diagram of an alternate embodiment of a gauge means for measuring the movement of the cantilevered sensing beam; and

FIG. 7 is a block diagram of the electrical control and operative equipment for the embodiments of FIGS. 1 through 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to the drawing wherein like numerals of reference indicate corresponding parts throughout the several figures, a platform 1 of an enclosure 2 has an orifice 3 through which a rod 4 having at least one flat side is disposed for axial movement.

A retaining strap 5 manufactured for example from -inch spring steel and having an aperture 6b of the same cross sectional shape as the rod 4 (which fits therethrough to prevent relative rotation therebetween) is nonrotatably attached at a distance from the orifice 3 by screws or otherwise, to the platform 1. A mounting plate 5a having an aperture 6a of the same cross sectional shape as the rod is similarly attached by screws or otherwise, to the sleeve 7 but perpendicular to the retaining strap 5, providing an attachment for the pellet hopper assembly. The apertures, orifice and rod, 6b, 6a, 3 and 4 respectively, are axially aligned.

The bottom of the rod 4 and the underside of the retaining strap 5 are non-rotatably connected to the top of the internally threaded sleeve 7 by screws or other conventional fastening means. A screw 8 engages the internal thread of the sleeve to form a screwjack.

The output shaft (unnumbered) of a conventional electric motor 9 is connected to the input of a speed reducing gear 10 shown as a worm gear drive, to increase the torque delivered by the motor. The speed reducing gear output shaft 10a is disposed in a drilled hole 8a in the bottom of the screw 8 and held therein with set screws 8!). The motor and speed reducing gear are supported in the enclosure 2 by conventional means (not shown).

It should be understood that reversing the rotation of the motor 9 moves the sleeve in the opposite axial direction, for example, forward rotation of the motor moves the sleeve up and reverse rotation of the motor moves the sleeve down. In one embodiment of the present invention, the electric motor is a series wound motor which is reversed by reversing the polarity of the input thereto in a standard manner and will be covered with reference to FIG. 4 below.

A first pressure plate 11a is non-rotatably mounted on the top of the rod 4 in known manner, for example, fitting a portion of the rod into a hole (not shown) drilled in the reverse face of the first pressure plate 11a and preventing movement therebetween with a conventionally tightened screw set (not shown).

The first pressure plate 11a thus follows the axial motion of the sleeve 7 which, being prevented from rotating by the retaining strap 5, only moves axially in response to rotation of the screw 8 by the motor 9 through the speed reducing gear 10.

The obverse face of the first pressure plate 11a can be a flat surface (see (FIG. 3) or a flat surface with a semicylindrical rise 12 across the center thereof (see FIGS.

'4 1, 2, 4, 5, and 6). The semi-cylindrical rise can be formed, for example, by welding the fiat side of a semicylindrical rod to the fiat surface of the first pressure plate 11a along a diameter of the first pressure plate.

A second pressure plate 11b is spaced away from and is in axial alignment with the first pressure plate 11a. The obverse face of the second pressure plate conforms to and faces the obverse face of the first pressure plate. When the semi-cylindrical embodiment is used, it is preferred that the first and second pressure plates are oriented with the semi-cylindrical rises thereon in line with each other.

When the obverse faces of the first and second pressure plates 11a and 11b, respectively, are flat, which is the conventional configuration, line contact is made along the length of the cylindrical catalyst pellet P, which is placed therebetween and the applied stress on the catalyst pellet is radial. When the obverse faces of the first and second pressure plates have the semi-cylindrical rise embodiment as described herein, point contact is made on the catalyst pellet placed therebetween with its axis oriented at a right angle to the axes of the semi-cylindrical rises. The latter contact with the catalyst pellet is desirable when the cylindrical pellet is irregular and crooked, for example, when the cylindrical pellet is extruded since line contact with fiat plates would lead to abnormally high local stresses and unrealistically low scattered results during samplin A pair of parallel wires 13, spaced apart from each other a distance slightly less than the diameter of the catalyst pellet, extend over the first pressure plate 11a to hold the catalyst pellet in place on the parallel wires for testing. When the first and second pressure plates, 11a and 11b respectively, have the semi-cylindrical rise 12, the axes of the parallel wires 13 and semi-cylindrical rise of the first and second pressure plates are oriented at right angles to each other to make point contact with the catalyst pellet supported on the parallel wires as described above. The pair of parallel wires 13 can be supported from any part of the apparatus as would be conventionally desirable with various embodiments particular ways will be described below.

The semi-cylindrical rise 12 in one embodiment, has a radius substantially equal to the nominal radius of the pellet material so that the local unit stress is more nearly normalized. This stress application is more nearly independent of surface irregularity and more nearly simulates the stress state of, for example, catalyst pellets in a reactor, i.e., adjacent catalyst pellets are randomly oriented and tend to press against each other at a point.

A pair of angle members 14 spaced apart in mirror image alignment, are axially spaced away from the orifice 3 and equidistantly spaced away from opposite sides of an extended center line of the orifice and have one leg each aflixed, by welding or other fastening conventional means, to the base 1.

A cantilevered sensing beam 15 is parallel to the axis of the pair of angle members 14 and supported in the space therebetween on a supporting reaction point 16 with the free end of the cantilevered sensing beam extending over the orifice.

The reverse face of the second pressure plate 11b is non-rotatably connected to the underside of the free end of the cantilevered sensing beam 15.

The supporting reaction point 16 is, for example, a piece of sheet metal forming a knife edge 17 held on a piece of rectangular cross section bar stock 18, by known means. The bar stock is held in place on the free legs of the pair of angle members with screws 19 or other known means. The central portion of the cantilevered sensing beam in one embodiment is notched (not shown) at the line of contact with the supporting reaction point 16 for precise measurement. A restraining bar 20 oriented at right angles to the cantilevered sensing beam 15 and disposed thereacross between the supporting reaction point 16 and the free end, is non-movably fixed at opposite ends to the standing legs of the pair of channels, for example, by fitting the ends of a cylindrical restraining bar into pre-drilled tight fitting holes in the sides of the free legs of the pair of channels, directly opposite each other. The supporting reaction point 16 and the restraining bar 20 form a couple on the cantilevered sensing beam 15 which resists the torque produced by an upward force exerted against the obverse face of the second pressure plate 1117 at the free end of the cantilevered sensing beam.

When the compression resistance of a catalyst pellet is being measured on the inventive apparatus, the first pressure plate 11a is moved up by the sleeve 7 forcing the catalyst pellet resting on the pair of parallel wires 13 against the second pressure plate 11b. As the catalyst pellet resists fragmentation the cantilevered sensing beam is forced up at its free end. Gauge means 21 are provided in alternate embodiments to measure either the extent of the upward movement of the free end of the cantilevered sensing beam or the flexure of the cantilevered sensing beam caused by the upward movement of the free end of the cantilevered sensing beam by known means, for example, in the former (see FIG. 6) a conventional dial indicator (unnumbered) which is well known in the machinists art and in the latter (see FIG. 4) a conventional strain gauge (unnumbered) applied at the point of fiexure. The strain gauge (see FIG. 7) can be conventionally electrically connected to a conventional chart recorder (not shown) 22a which receives power for operation as described below.

A calibrated readout device 22 is connected electrically, mechanically or otherwise, by conventional means (unnumbered) to the gauge means to indicate the compressive force exerted on the catalyst pellet. The calibrated meter can be any well known type of conventional meter, for example, a dial gauge or a chart recorder.

When the maximum compressive resistance of the catalyst pellet is reached, the calibrated readout device 22 indicates the amount of compressive force being resisted by the pelletized material and at the very next instant, due to the continued increase in pressure by the upward movement of the first pressure plate 1111 the catalyst pellet fragmentates, allowing the cantilevered sensing beam 15 to return to normal. The calibrated readout device 22 indicates the highest compressive force registered and in the case of a chart recorder gives a continuing history of the compressive force; this is desirable when the test procedure is automated.

To damp the vibrations and balance the fixed end of the cantilevered sensing beam 15, a resilient member 23, for example a spring, can be connected to a hole (not shown) in the fixed end which is extended in one embodiment of the cantilevered sensing beam, and to the base 1, for example through a hole in one end of an angle clip 24 atfixed to the base 1 by conventional means such as a screw (unnumbered).

The graduations can be marked on the calibrated meter by any known means, for example a calibrating bar 25 can be used. The calibrating bar in one embodiment is disposed above and parallel to the cantilevered sensing beam 15. A knife edge fulcrum 26 whose length is oriented perpendicular to the length of the calibrating bar rests on a support block 27 which is in turn supported on the edges of the two upstanding legs of the pair of angle members 14. The support block 27 is attached to the pair of angle members by screws 28 or other known means. A V-shaped notch is made in the bottom of the calibrating bar in an embodiment (not shown) wherein the knife edge fulcrum 26 supports the calibrating bar 25 perpendicular to its length, for an exact measurement of the moment arm which is necessary to the calibration procedure, as will be shown below.

One end of the calibrating bar 25 extends over the orifice 3 where it is connected, for example, by a square yoke 29 fitted at its bottom with an attaching threaded stud 29a, axially in line with the orifice, which is, for example, screwed into the top pressure plate 11b and locked by a threaded nut 29b to the top of the cantilevered sensing beam. The yoke 29 fits on the calibrating bar and forms a knife edge (unnumbered) where it rests on the calibrating bar.

A rear yoke 30 similar to the square yoke but disposed at the opposite end of the calibrating bar and in one embodiment extending over the platform, has a hook 31 conventionally supported from the center portion of the lower section thereof. The rear yoke has a knife edge (unnumbered) where it rests on the calibrating bar which is notched to define a narrow line where the force is exerted on the calibrating bar and thus gives greater accuracy when measuring a moment arm about which a force is directed. Weights 32 can be placed on the hook in a conventional manner in small increments, as desired, for greater accuracy.

To calibrate the meter, weights 32 are incrementally placed on the hook and the corresponding indication of the calibrated meter 22 is recorded. Moment arms, for example, X and Y (see FIG. 4), are measured and the force at the square yoke determined from the conventional moment equations from physics, i.e., the product of the weight and the distance X all divided by the distance Y is equal to the force in question. This force is then recorded on the calibrated meter 22. With this test repeated for ditierent weights the meter can be conventionally marked and the date of calibration recorded. It can be seen that this force is the same as a compressive force which would be exerted against the free end of the cantilevered sensing beam by the second pressure plate.

In one embodiment, a control lever 33 can be conventionally radially attached to extend from the periphery of the sleeve 7. A conventional upperlimit switch 34 and lowerlimit switch 35 are attached conventionally by screws or otherwise to the enclosure 2 in position for the control lever 33 to contact the control button (not numbered) of the upper-limit switch and lower-limit switch when the sleeve travels to the maximum desired upward and downward vertical positions, respectively. The limit switches prevent excessive vertical travel of the sleeve in the upward and downward directions, for example, by interrupting power to the motor when the distance between the first and second pressure plates is less than one-half or greater than one and one-half times the diameter of the catalyst pellet.

In reference to FIG. 7, the upperand lower-limit switches, 34 and 35 respectively, are normally closed switches serially connected to each other and to a source of electricity 36 at one end and to the motor 9 at the opposite end. Thus, when either the upper or lower limit switch is mechanically tripped, for example, by the control lever urging the control button into a switching position, the electrical circuit from the motor 9 to the source of electricity 36 is opened. This avoids a loss of time during successive measurements, because of overtravel of the sleeve and also prevents possible damage especially to the pair of parallel wires 13 and the sensing bar 15, by the meeting of the first and second pressure plates, 11a and 11b respectively.

In one embodiment of the present invention, the mo tor 9 is a series-wound DC motor which derives its energy from the source 36. The source is any convenient source of electrical energy, as for example a conventional volt, single phase, alternating current house circuit (shown but not numbered) available through a wall outlet (not shown). An on-0E switch 37, for example a toggle switch, is conventionally provided to energize or deenergize, respectively, the motor and any other equipment requiring electricity from the source to operate and is wired in series with the source 36, as will be described below.

The alternating current is converted to direct current by a conventional rectifier 38 connected in series through the on-off switch to the source 36. A potentiometric device 39 is connected in series to the rectifier 38 at one end and through the upper and lower limit switches, 34 and 35 respectively, to the motor 9. The potentiometric device 39 acts to vary the voltage delivered to the motor 9. The speed of the series-wound motor 9 is changed in response to the voltage being varied at the input terminals (not shown) of the motor 9 by the potentiometric device 39. Thus, the time rate of increase in compressive force exerted on the cylindrical pellet can be controlled to give the greatest sensitivity.

In order to retract the first pressure plate away from the second pressure plate, a conventional polarity reversing relay 40 is provided serially in the rectified portion of the electrical circuit between, for example, the motor 9 and the upper-limit switch 34. This provides the polarity reversing relay 40 with a direct current voltage for proper operation. The polarity of the voltage supplied to the motor 9 when reversed by the polarity reversing relay 40, changes the direction of rotation of the motor 9 as is well known for a series wound DC motor.

The chart recorder 22a is connected in series to the on-off switch 37 when used and the strain gauge 21a is connected directly to the chart recorder 22a and adapted to deliver to chart recorder 22a information to chart.

In one embodiment adapted for manual operation (refer to FIG. la), a feed mechanism 41 consists of a V- shaped trough 42 and is supported on mounting plate a. The bottom of the V 42 is substantially level with the obverse face of the top of the semicylindrical rise 12 of the first pressure plate 11a or with the obverse face itself when the obverse face is fiat. The cylindrical catalyst pellets P can be pushed along the V onto the pair of parallel wires 13 until the catalyst pellet is stopped by the closed end of the pair of parallel wires Where the catalyst pellet is in position for testing.

The pair of parallel wires 13 can be supported from the end of the V-shaped trough 42 with this embodiment. Holes can be drilled in the end of the V-shaped trough and the end of the pair of parallel wires can be fitted therein and afiixed thereto by welding or other conventional means.

An alternate embodiment of a feed mechanism 41 adapted for semi-automated or automated operation (refer to FIG. 2), comprises a pellet hopper 45. The pellet hopper includes a rectangular conduit 46 disposed 01f to the side of the pressure plates 11a and 11b and supported on one end. The hollow interior of the rectangular conduit forms the storage portion of the pellet hopper 45 and a conventional feed slot 47 overlooks the obverse face of the first pressure plate 11a. The bottom of the feed slot 47 is slightly higher than the top of the semi-cylindrical rise or flat face of the obverse face of the first pressure plate to prevent interference as the pellet P is moved along the pair of parallel wires 13. The pair of parallel wires 13 extend from below the bottom edge of the feed slot where they are connected to the side of the rectangular conduit by conventional means.

A standard conventional plunger housing 48 is supported longitudinally on mounting plate 5a in open communication with the side of the pellet hopper opposite the feed slot, and disposed to support the bottom end of the rectangular conduit 46 to which it is connected by welding or otherwise.

A push rod 49, connected to an end plate 50, is axially disposed in the plunger housing 48. A feed bar 51 is connected to the end plate 50 so that it is in line with the feed slot 47 to permit urging of the bottom catalyst pellet from the pellet hopper through the feed slot and onto the pair of parallel wires 13. This is accomplished by urging the push rod toward the feed slot.

The push rod extends outside the plunger housing 48 (opposite the pellet hopper 45) through an orifice 52 in the plunger housing 48 in a conventional manner.

A compression spring 53 is conventionally disposed on the push rod 49 within the plunger housing 48 between bulkhead 48a and collar 54. A collar 54 is connected onto the push rod and fixed in position by a set screw (unnumbered) or other known means, thereby limiting the return of the push rod to a desired position.

In a further alternate embodiment of this invention (see FIGS. 5 and 7) a pressure line cleaning assembly 55 is provided wherein the catalyst pellet after being fragmentated can be blown off of the first pressure plate 11a by a compressed gas, for example, air or nitrogen. A gas conduit 56 of, for example, As-inch diameter aluminum tubing is in communication with a cylinder of compressed gas 57, or other source, spaced away from the apparatus and maintained at a pressure of about 30 pounds per square inch. The gas conduit 56 extends to adjacent the obverse face of the first pressure plate 11a where the open end 58 can be convergent or otherwise. The gas conduit can be fastened to the apparatus by conventional means.

The gas conduit is closed to the flow of gas by a conventional normally closed valve 59 which opens to allow compressed gas from the cylinder to force the fragmented catalyst pellet off of the first pressure plate. A solenoid 60 can be used to switch the valve 59 and is manually operated to the open position when its button is depressed. The solenoid is serially connected to the power source 36 through the on-ofi switch 37.

The present invention encompasses the use of any type of feed mechanism 41 capable of manually or automatically positioning the catalyst pellet onto the obverse face of the first pressure plate 11a and is in no way limited to the modifications set forth herein which are by way of example and not to be considered exclusive.

Other modifications and variations of the above invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A compression resistance testing machine for pelletized material in which said pelletized material is crushed between an ever-increasing force exerted by said testing machine, including:

(a) a screwjack,

(b) motor means connected in a driving relation to the screw of said screwjack,

(c) cantilevered sensing beam, the free end thereof extending above said screwjack,

(d) pressure plate means connected to the top of said screwjack and to the bottom of said cantilevered sensing beam and having disposed in said pressure plate means a bed for supporting said pelletized material, whereby when said screwjack is urged toward said cantilevered sensing beam by said motor means, said pelletized material is compressed between said pressure plate means, and

(e) gauge means in communication with said cantilevered sensing beam adapted for measuring and indicating the movement of said cantilevered sensing beam, said gauge means being calibrated to record load exerted against said cantilevered sensing beam by the movement of said pressure plate means toward said cantilevered sensing beam, whereby said pelletized material placed on said bed of said pressure plate means is compressed by the axial advance of said screwjack as said screwjack is driven by said motor means, said cantilevered sensing beam being flexed while said, pelletized material resists compression, the fiexure of said cantilevered sensing beam ending abruptly as said pelletized material fragmentates upon the maximum compression resistance of said pellet being exceeded, and said gauge means indicating the maximum compression resistance of said pelletized material at fragmentation.

2. A compression resistance testing machine as defined in claim 1, which additionally includes:

(a) a platform with an orifice therein which is coaxial with said screwjack and upon which is supported said cantilevered sensing beam, said screwjack being disposed for axial movement within said orifice, and

(b) a retaining strap secured to said platform at one end and having an aperture therein with at least one flat side coaxial with said orifice, in which said pressure plate means having a mating cross-sectional portion disposed for axial movement therethrough, whereby said pressure plate means is prevented from rotation by said retaining strap.

3. A compression resistance testing machine as defined in claim 2, wherein said cantilevered sensing beam is further restrained at the fixed end thereof by a resilient member being connected at opposite ends to the fixed end of said cantilevered sensing beam and to said platform, whereby vibrations in said cantilevered sensing beam are rapidly dampered for more accurate and quicker measurements.

4. A compression resistance testing machine as defined in claim 1, which additionally comprises dispensing means including a pellet hopper disposed with its axis vertically aligned and having a window in the periphery thereof vertically spaced adjacent said bed of said pressure plates, said Window and the chamber of said pellet hopper being slightly larger than said pelletized material, a conduit feed disposed at an angle to and in communication with said pellet hopper, and a plunger axially disposed in said conduit feed and adapted to slide said pelletized material through said pellet hopper and out said window, whereby upon said plunger being urged to move through said conduit, said pelletized material in said pellet hopper is pushed through said window and dropped onto said bed of said pressure plate means so that a compressive load test can be made thereon by the compression resistance machine.

5. A compression resistance testing machine as defined in claim 1, wherein a pressure line cleaning assembly is provided and adapted for disposing of said fragmentated pellet after said test is over, said pressure line cleaning assembly including a gas conduit opening adjacent to and in a perpendicular plane to the bed of said pressure plate means, a source of compressed gas in communication with said gas conduit, and a solenoid operated normally closed valve disposed in said gas conduit opening and adapted for preventing the flow of gas therethrough when in the closed condition, whereby upon said solenoid being operated said compressed gas is discharged out of said gas conduit across said ohverse face of said first pressure plate, carrying with it said fragmentated pelletized material.

6. A compression resistance testing machine as defined in claim 1, wherein said motor means is a seriallywound electric motor.

7. A compression resistance testing machine as defined in claim 6, wherein a potentiometric means is electrically connected to said serially wound electric motor at one end and to a source of voltage at the other end so that variation of the potentiometric resistance varies the voltage across said series winding, thereby controlling the speed of said serially wound electric motor.

References Cited UNITED STATES PATENTS 2,791,120 5/1957 Dietert et al. 73-94 X 3,140,601 7/1964 Weyland et al. 73-95 X FOREIGN PATENTS 957,131 5/1964 Great Britain 7394 145,386 5/1962 U.S.S.R. 73-94 CHARLES A. RUEHL, Primary Examiner 

